VITTARIA LINEATA 197 
and then cuts off the terminal portion by a partition wall, making 
two cells of unequal size, the lower being much larger (/. 
400, 41). The apical cell becomes almost spherical, and the next, 
wall formed in it is funnel-shaped, connecting with the wall 
previously formed in such manner as to separate a central cell. A 
third wall is now formed: in the apical portion of the peripheral 
cell cutting off a cap cell shaped like a watch glass (f. 43-45). 
The antheridium now consists of four cells, a pedestal cell, a hemi- 
spherical central cell enclosed by a cylindrical peripheral cell, and 
crowned by a cap cell (f. 42). Further division occurs in the 
peripheral cell in rare instances. The first division wall in the 
central cell is generally longitudinal, and the second one is at 
right angles to it, and this sequence is followed during the forma- 
tion of an indefinite number of mother cells (f. 42, 44). 
An antherozoid is produced in each mother cell The con- 
necting walls of the mother cells dissolve and the antheridia lie free 
in the antheridium (£ 48a). When the antheridium is ripe the 
antherozoids are ejected by the swelling of the peripheral cell and 
of the upper contiguous portion of the pedicel (f. 49) which is 
pushed up into the antheridial cavity; the cap cell is ruptured 
either at the center or at one side. When the antherozoids escape 
from the antheridium they are enclosed by a thin membrane, which 
is thrown off shortly after their liberation. The antherozoids un- 
coil with a whip-like motion, curling and uncurling very rapidly 
during a few seconds, the movements of the cilia increasing in 
rapidity. The action of the cilia propels the antherozoid at a com- 
paratively great speed, and they remain active for some time 
(Æ 50). 
Four antheridia were seen in the act of discharging the an- 
therozoids: the latter escaped in rapid succession, although two 
or three came out together in some instances. It was not difficult 
to count the emerging antherozoids, and two antheridia were found 
to contain twelve and another twenty-four. One antheridium was 
emptied in a little more than a minute, and the antherozoids burst 
the enclosing membrane in forty seconds or less after emergence. 
The entire number (twelve) had freed themselves in this manner in 
less than two minutes from the time action began. A portion of 
the mother cell in the form of a hyaline sphere with a granulated 
